Method of making tubular inserts



' Oct. l, 1940. -l Q J, KELLER 2,216,201

BULAR INsERTs Filed Deo. 22, 1934 gif/ /Jyj

UNITED STATES PATENT OFFICE 1;,

Patented Oct. 1, 1940 METHOD or MAKING TUBULAR INSERTS corporation of Delaware Application December 22, 1934, Serial No. 758,750

6 Claims.

` This invention relates to the manufacture of distributor cap inserts and more particularly to a` novel method of manufacturing such inserts.

It is among the objects of the present invention to sever slugs from intermittently fed bar stock and to form the slugs into shells by a cold heading and a following extruding operation.

` It is another object of the present invention to face the open end of a shell. It is `another object of the present invention to form an external bead on a shell.

f ItisanOther object of the present invention externally and longitudinally to knurl a shell.

` Further objects and advantages of the present invention will be apparent `from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present inventions clearly shown.

`In thedrawing: l

Fig.` 1 discloses the severing of a slug from bar stock.

, Fig.2 illustrates a Vcold heading operation performed on a slug.

Fig. 3 illustrates the extruding of a cold headed slug into shell form.

Fig. 4 illustrates a facing operation performed on `a shell. f

Fig. 5 illustrates a knurling operation performed on `a faced shell.

Fig. 6 illustrates a beadingoperation performed onfa knurled shell.

Fig. '7 is a fragmentary section taken on the line 'I-JI of Fig. 6. l

Fig. 8 is a perspective view of a finished insert.

The consecutive gures in the drawing illustraterprogressive steps in the novel method of manufacturing distributor cap inserts l0. With reference to Fig. 1, preferably cylindrical bar stock I2 of good conductive material, such as copper, is fed in the direction of arrow I4 in Fig. 1 by any suitable means such as for instance two continuously or intermittently rotated feed rollers .(not shown) which yieldingly engage the bar stock. The bar stock is fed through an aperture I5 of a stationary shear member I6 and into the aligned aperture I'I of a movable shear member I8 until `the forward end 20 of the bar stock engages a stationary stop 22, whereupon further feeding of the bar stock is prevented. The movable shear member I8 is thereafter movedin any suitable manner relative to the stationaryshear member I6 whereby a slug 24 is severed from the bar stock.

This `slug 24 is then inserted in any suitable manner into a die 26, preferably by the movable shear member I8 which may bring the slug into alignment with the aperture 28 of the die, whereupon `an axially movable ram 30 pushes said slug from `the movable shear member I8 into the aligned' aperture 28. The movable shear member (c1. zei-155.55)

I8 is then returned into alignment with the stationary shear member I6 whereupon the bar stock I2 is again fed into engagement With the stop 22.

As previously explained, the ram 30, While advancing in the direction of arrow 32 in Fig. 2,

pushes the slug 24 from the movable shear mem,`

ber I`8 into the aligned aperture 28 of die 26, and upon continued movement in that direction theram cold-heads the slug into the shape shown in Fig. 2. It will be noticed that the cold-headed slug has a cylindrical portion 34 of substantially the same diameter as the original slug, a reduced stem 36 in axial alignment with the cylindrical portion and a dish-shaped end surface 38.

While the cold-headed lslug remains` in the same die 26, a reciprocablevextruding tool 40 is moved in any suitable manner in the direction of arrow 42 in Fig. 3 into the position shown therein, whereby the cylindrical portion 34 of the coldheaded slug is extruded into the shape of a shell as shown in Fig. 3. During movement of the extruding tool 40 in the direction of arrow 42, the metal of the cold-headed slug is caused to flow between the head 44 of said tool and the aperture 28 of the die 26 until the tool reaches the end position `shown in Fig. 3.

As will be noticed from Figs. 2 and 3, itis preferable to extrude the stem 36 to its `full length in two operations, primarily to prevent the cold heading ram 30 from exerting too great an axial pressure against the slug during the cold-heading operation. Therefore, the ram 30 causesthe partial formaton of the stem and the extruding tool 40 elongates said stem to its proper lengthby forcing the metal not only between the tool head 44 `and the die `aperture V28 but also toward the stem. In` this manner the pressures exerted by the ram 30 andthe extruding tool 40, respectively, are approximately thesame and the wear and tear on these tools is, therefore, substantially equal. vA knock-out pin 46 `projects into the die 26and in its inoperative position determines the length of the stem 36 as can be readily understood. The knock-out pin 46 maybe reciprocated in any conceivable manner so as to remove the shell 45 fromthe die 26 after the retraction of the extruding tool 40 therefrom. Likewise the extruding tool 46 may be reciprocated in any suitable manner'.

After the shell 45 has been thus obtained, it is received by a rotatable stub shaft 48, having a frusto-conical end portion 50 which engages the conev shaped internal bottom 52 of the shell. A rotatable thrust member 54 engages the stem 36 of the shell and clamps the cone shaped internal bottom 52 thereof into driving engagement with the frusto-conical shaft end 53. Either the stub shaft 48 or the thrust member 54'may beA order to face the same.

After removal of the shell 45 from the stub shaft 48, it is passed over a cylindrical bar 60".y

and received with its open end in a recess 62 of a ram 64. ram 54 are reciprocable, however, the ram 64 must be reciprocable independently of bar 60. The faced shell 45 is passed over bar 60 while both, the ram 54 as well as the bar 60, are in a position most retracted from a die 68. Upon movement of ram B4 and bar 60 with the thereon. deposited shell 45. in the direction of arrow A66* in Figg, the shell is moved into the die 68, and more particularly the periphery of the shell is forced past an annular rib 'l0 of die 68 which is provided with longitudinaLequally spaced cutting teeth 'l2 for knurling the outer periphery of the shell until the shell surface 'i4 comes to rest against the corresponding surface 'I6 of the die as best shown in Fig.` 6. Therefore, the shell is knurled only over part of its length as appears best Vfrom Fig. 8. The die 68 is also provided with an annular recess 18 adjoining the annular rib '10. When the shell 45 comes to rest onthe die surface 16, bar 60 ceases to reciprocatev but remains in the position shown in Fig. 6, Whereas the ram 64 continues its movement into the position shown in Fig, 6. Such continued movement of the ram 64 relative to bar 60 causes a part of the shell wall to fold i outwardly into the. annular recess 18 of die 68, thereby forming an external annular bead 80. 'The bar 60 prevents 'the shell Wall from collapsing inwardly wherefore the `bead must be necessarily an externally raised bead as can be readily understood. It will be noticed from Fig'. 8 thata cylindrical continuation 84 of the shell wall proper emergesfrom-the annular bead 8U. In order to prevent during the bead formation an `outward collapse of theshellwall portion 84, the same is received by the annular recessi 62 lof ram 64. After a shell has thus been knurled and provided with an annular bead, ram 64 as well as bar 6U' are withdrawn from die 68 and the finished insert is ejected from said die by a knock-out pin190 which is reciprocable in any suitable manner.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form,it is to ybe understood that other forms might-be adapted, all coming within the scope of the claims which follow.

I claim:

1. Ina method of manufacturing distributor cap inserts, the steps of causing relative axial movement between they cup of an insert and a knurling die to knurl the former, and stopping relative axial movement between a portion of saidcup and the die while continuing such relative movement towardsaid cup portion between another cup portion and the die whereby the cup part between said portions is upset into an Both, the bar 60 as well as the from a billet an object having a cup-shaped portion and an integral axial extension comprising placing a billet in a die, punching the billet when it is in the die, by an axially moving punch to cause it to spread radially of the axis sumciently to cause its transverse cross section to become that of the die, and without removing the billet from the die, punching it by an axially moving punch other than the one rst used, to cause the metal thereof to flow in two opposite axial directions simultaneously and thus form a cup and an axial extension.

, 4. In a method of manufacturing distributor cap inserts, the steps of forming a metal slug into a cup-shaped element, supporting the cupshaped element throughout its length on a mandrel of the size of theinner diameter of the cup, forcing the cup-shaped element while supported on said mandrel, into a cup-shaped die part of which has a diametersubstantially equal to that of said element and a part of greater diameter, and applying pressure to one end of the cup-shaped element after the mandrel has completed its movement and while the said element is supported on the mandrel and held against axial movement within the die, so as to expand a part ofv said element into the larger part ofthe die while preventing inward collapsing of said element in order to form a bead on the outer surface thereof.

5. In a method of manufacturing distributor cap inserts, the steps of forming a metal slug into a cup-shaped element, supporting the cupshaped element throughout its length on a mandrel of the size of the inner diameter of the cup, forcing the cup-shaped element While supported on said mandrel, into a knurling die part of which has a diameter substantially equal to that of said element and a part of greater diameter to knurl the outer surface of said element, and subsequently applying pressure to the open end of said element while supported on said mandrel and while held against axial movement within the die, to expand a part of said element into the larger part of the die in order to form a bead on the outer surface thereof.

46. lInj'a Vmethod of manufacturing distributor cap inserts, the steps of forming a metal slug into a cups-shaped element, supporting the cupshaped element throughout its length on a mandrel of the size ofthe inner diameter of the cup, forcing the cup-shaped element while supported on said mandrel, into a die part of which has a diameter substantially equal to that of said element and a part of greater diameter, moving a ram against the open end of the cupshaped element after the motion of the mandrel has stopped and while the element is supported on the mandrel and held against axial movement between the mandrel and the Wall of the die in order to apply pressure to the end of said element so. as to expand a part thereof into the larger portion of `the die for the purpose of forming a bead on the outer surface of the elementrand prevent collapsing of said element during the formation of the bead.

CLARENCE J. KELLER. 

